1. Field of the Invention
The present invention relates to a fluid handling apparatus and a method of handling a fluid, and particularly to a fluid handling apparatus and a method of handling a fluid that are suited for handling a gaseous fluid in the field of microfluidics.
2. Description of the Related Art
For pumping fluids, i.e. gases and liquids, numerous functional principles are known in microfluidics. From Goulpeau, J. et al., “Experimental study and modeling of polydimethylsiloxane peristaltic micropumps.”, Journal of Applied Physics 98, 044914, 2005; and Unger, M. A., et al., “Monolithic microfabricated valves and pumps by multilayer soft lithography,” Science Vol. 288, 2000, pages 113-116, and EP 1065378 B1, it is known to employ elastomers, predominantly PDMS (polydimethylsiloxane), as an elastic membrane element and deflect the same for example by external pressure applied in a second channel plane, in order to handle liquids. Thereby, liquids may be displaced/pumped.
Magnetic deflection of such membrane elements in fluid handling apparatuses is also known. For example, Yamahata, C., et al., “A Ball Valve Micropump in Glass Fabricated by Powder Blasting”, Sensors and Actuators B-Chemical 110 (2005), pages 1-7; and Yamahata, C., F. Lacharme, and M. A. M. Gijs. “Glass valveless micropump using electromagnetic actuation”, Microelectronic Engineering 78-79 (2005), pages 132-137, disclose the employment of permanent magnets connected to an elastic membrane. For deflecting the membrane, an electromagnet is employed here.
A micropump disclosed in Pan, T. R., et al. “A magnetically driven PDMS micropump with ball check-valves” Journal of Micromechanics and Microengineering 15.5 (2005), pages 1021 to 1026 utilizes a permanent magnet attached on the spindle of a minimotor for periodic excitation of a magnetic plate disposed on a membrane of a micropump. The spindle rotates below the pumping chamber, so that the pump is operated at the rotational frequency of the motor.
From WO 97/10435 and from Stehr, M., et al., “The VAMP—A new device for handling liquids or gases” Sensors and Actuators A-Physical 57.2 (1996), pages 153-157, a check-valveless fluid pump is known, which comprises a pump body, a displacer in form of an elastic membrane, via which an opening can be closed and opened, and an elastic buffer adjoining a pump chamber formed in the pump body.
From Günther, A., et al., “Micromixing of miscible liquids in segmented gas-liquid flow”, Langmuir 21.4 (2005), pages 1547-1555, a microfluidic system for efficient mixing of two miscible liquid flows by introducing a gas phase is known, which generates a segmented gas-liquid flow and completely separates the mixed liquid and gas flows in a planar capillary separator. Here, liquids and gases are introduced into microchannels by external pumps, wherein by suitable choice of the flow conditions at a joint a two-phase flow results, in which liquid and gas segments alternate along the channel. The segmented gas-liquid flow was visualized by the addition of a fluorescent dye to the liquid phase.